grblgru

GrblGru

- Operating Instructions

Version 3.44

toe@home

January 29, 2020

Contents

Before you start reading, you should note the following ...

What is

GrblGru

2.1

The name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.2

The Basic functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.3

The Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.4

Simulation Operation

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.5

Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Download and Installation

3.1

Hardware and Software Requirements

. . . . . . . . . . . . . . . . . . . . . . . . . . .

3.2

Where can I get the program from ? . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3.3

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Projects to Try

4.1

Project 1, Cut out the Moose

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.1

Load Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.2

Jobs and Job Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.3

The Tool Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.4

Elements of the 2D view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.5

Assign a Job to the Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.6

Starting points and Tabs position . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.7

The Second Job

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.8

Dimensions of the component . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.9

Start Position Marker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.10 The Tool Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.11 Preview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.12 Save Project

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.13 The Generated Gcode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2

Project 2: DXF template, the Coffee Cup Traye

. . . . . . . . . . . . . . . . .

4.2.1

Loading Geometry Data from DXF templates . . . . . . . . . . . . . . . . . . .

4.2.2

The Box Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2.3

Save Geometry Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2.4

Modification of the Geometrye . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2.5

Create Job with ‘Corner Overcut’ Parameter . . . . . . . . . . . . . . . . . . .

4.3

Project 3: Bitmaps Drilling, the Smiley Face brooch

. . . . . . . . . . . . . . .

4.3.1

Drilling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.3.2

Loading Bitmaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.3.3

The Operating Mode ’DRILL’

. . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4

Project 4: Projection onto a rotary axis, the Viking bowl

. . . . . . . . . . . .

4.4.1

Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4.2

Scanning the workpiece . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4.3

Load, scale and position sketch . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4.4

Create a job and start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Details on other Program Operations topics

5.1

3D graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.2

Options to Load Geometry data

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.2.1

Via the Menu - Import DXF or Import SVG

. . . . . . . . . . . . . . . . . . .

5.2.2

With Drag & Drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.2.3

By selecting Recent Files

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.2.4

Load With ’Quick Load Last File’ button . . . . . . . . . . . . . . . . . . . . .

5.3

Ways to Create Jobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.3.1

In the Tree View: Drawing

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.3.2

In the Tree View: Toolpath . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.3.3

In the Tree View: Layer Name

. . . . . . . . . . . . . . . . . . . . . . . . . . .

5.3.4

In the Graphics Window: Pull up the window . . . . . . . . . . . . . . . . . . .

5.3.5

In the Graphics Window: Click on Paths . . . . . . . . . . . . . . . . . . . . . .

5.3.6

Last Used Job

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.4

Options to Mark Elements in the 2D view . . . . . . . . . . . . . . . . . . . . . . . . .

5.5

DXF templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.1

Rectangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.2

Triangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.3

Ellipse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.4

Breadboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.5

Spur gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.6

Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.7

Bolt Circle Calculator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.8

Multi Drill Circle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.5.9

Puzzle Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.6

USEFUL Free programs to use with your CNC . . . . . . . . . . . . . . . . . . . . . .

5.7

Notepad++, a Editor for G-Codee . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Macros

6.1

Operating system Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2

Advanced Macro functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Administration of languages

How to Import your own 3D Machine Model

8.1

Can

GrblGru

simulate my machine ? . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.2

Construct the machine in CAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.3

Save Modules as STL

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.4

Create a new machine in the Machine Manager . . . . . . . . . . . . . . . . . . . . . .

8.5

Import STL files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.6

Reading out control values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.7

Tool Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.8

Rotary Axes position and direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.9

Input of the Reference Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

100

8.10 Limits (limit switches) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

102

8.11 Remaining settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

103

8.12 Special models (lathes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

105

Before you start reading, you should note the following ...

There is certainly a lot more to improve on

GrblGru

. Also there might be be some hidden bug, and

some things will only work if you do it in a specific order.
I just do it all at my free time because I enjoy programming. Please do not sting me if it does not
work out. Let me know, and I’ll try to fix it and make the next version a little better.

Ideas, suggestions for improvement and also criticism are always welcome.

Have fun with

GrblGru

What is

GrblGru

2.1

The name

Grbl is the name of a free great open source software that can interpret G-code and use it to convert
pulse and direction information to control the stepper motor power amps. Because

GrblGru

heads to

GrB in control mode, the name

GrblGru

is the logical continuation of the ’stupid’ name Grbl. No-one

really knows what it means. The pronunciation is also not clearly defined. I prefer ’GrabbelGru’ and
because I describe myself often enough, I use the written short form a simple ’GG’.

2.2

The Basic functions

GrblGru

is ...

•

a 3D simulator for milling and lathe

•

a GCode Sender forr

Grbl

TinyG

Mega-5X

and

g2core

•

a CAM program for milling and lathe work

•

a Tool for learning CNC technology without needing a ’real’ ’Machine

I have noticed only recently what immense advantages the use of virtual
simulations for training purposes offers. It would mean a great deal to
me if the program could be used, for example, to bring this great hobby
closer to young people. If any changes or adjustments are required, I am
willing to do so.

2.3

The Operating Modes

GrblGru

has 2 different Operating Modes:

•

Simulation Mode

for Virtual 3D simulation of CNC machine control

•

Control Mode

for Real control of a CNC machine with

Grbl

TinyG

Mega-5X

oder

g2core

operating system.

2.4

Simulation Operation

This operating mode is the original idea of the program. It was primarily intended to check existing
NC programs on a virtual machine and to show any collisions or problems.
This type of early ‘virtual machine’ has prevailed in the industry more and more in recent years be-
cause it saves valuable machine time detecting possible errors in advance.

When

GrblGru

is started, the mode by default is set to the ’Simulation’. This gives the following

situation.

GrblGru

visualization

Intern G-code interpreter

G-code

Figure 1:

GrblGru

in Simulation mode

There is no connection to a real controller. The NC program to be examined is loaded and the NC
commands are processed by the internal NC interpreter. The loaded 3D model is animated accordingly.
NC = Numerical Control.

In the appendix you will find the currently available 3D models of the milling machines and lathe
tools. So if someone is a little familiar with 3D and interested in visualizing his home-made machine,
I’m happy to help..

A special feature of the program, however, is that the user can also
import their own 3D models. As a result, it is possible to represent
every question or lathe as a simple model in

GrblGru

2.5

Control Operation

In this mode,

GrblGru

can connect to an Arduino UNO, a TinyG, an Arduino Mega 2560, or an

Arduino Due controller. The connection is made via the USB interface, which transfers both the NC
commands to the controller and the information about the current axis positions back to

GrblGru

uses this information to control the 3D model so that the 3D model is synchronized to the

’real’ axes.

GrblGru

automatically supplies the respective processor

not

with the

necessary operating software. The user must therefore ensure that the
processor is flashed once with the appropriate operating software before-
hand.
This has the advantage that it is usually possible to update the processor
at any time without

GrblGru

having to change it.

The main difference of these four controllers lies in the number of possible axes. For example, TinyG
can also control a Rotary axis, often called the Fourth axis, in addition to the three linear axes. In
addition, 2.5 A drivers are already mounted on this circuit board, to which you can connect your step-
per motors. For larger motors, however, the signals for controlling external drivers are also available.

At present the control of the G2core software on an Arduino DUE is still under construction. This
system provides 6 axes (linear and rotary), making it the ideal control for my 5-axis dreammachine
that I’ll have at some point. :) The Arduino Uno can only control 3 Axes, generally XY and Z. Some
people will repurpose one of the axes to control an accessory rotary axis but it is not a true 4th axis
since the repurposed linear axis is rendered nonfunctional.

An imaginative software designer has made a special GRBL Modification specifically for the Arduino
Mega 2560 board (with or without a RAMPS board) which can provide control of 5 axes (and possibly
a 6th eventually). This is called Mega-5X. The RAMPS board has places for small stepper drivers to
mount so the motors can be directly connected. If you use the Mega 2560 alone, there is a MEGA-5X
Pinout available to connect this board to External Stepper Drivers.

When

GrblGru

is started, use the Controller option to select Simulation,

Grbl

TinyG

G2core

GRBL-Mega-5x

. This will give you one of the following situations.

GrblGru

Arduino

axis positions

Gcode

pulse- and.
directions-
signals

Driver

Stepper

visualization

Controlling

G-code interpreter

lle

G-code

Figure 2:

GrblGru

in control mode with Arduino UNO (3-axis)

GrblGru

TinyG

axis positions

Gcode

pulse- and.
directions-
signals

Driver

Stepper

visualization

Controlling

G-code interpreter

lle

G-code

Figure 3:

GrblGru

in control mode with Arduino DUE (5-axis)

GrblGru

G2Core

axis positions

Gcode

pulse- and.
directions-
signals

Driver

Stepper

visualization

Controlling

G-code interpreter

lle

G-code

Figure 4:

GrblGru

in control mode with Arduino Mega-5X or Arduino DUE (5-Axis)

Additional information about Grbl and Co::

•

Grb

https://github.com/grbl/grbl/wiki

•

TinyG

https://github.com/synthetos/TinyG/wiki

•

g2core

https://github.com/synthetos/g2/wiki/What-is-g2core

•

Mega-5X

https://github.com/fra589/grbl-Mega-5X

Download and Installation

3.1

Hardware and Software Requirements

A few words about computer requirements..

GrblGru

runs on a PC with a Windows operating system from Win XP up to Windows 10. As a

basic component, Windows Framework 4.0 is required. Check that it has been installed and if not,
make sure to get it before trying

GrblGru

A faster computer is particularly advantageous in graphics activities and will be a bit more fun. My
personal preference consists of a fast desktop computer for developing and simulating the models, and
an old computer in the basement to control the CNC machine.

3.2

Where can I get the program from ?

Answer. From my new website:

http://GrblGru.com

The site is currently still under construction. At the moment you can only download the released
(release) and the current test version (beta).

In the release version, there should no longer be any major errors. In contrast, I use the beta version
to make my current status available to some ’brave’ testers who have volunteered themselves.
More information will be made available as time allows.

3.3

Installation

The setup is done by simply starting the installer file. The installation time is only a few seconds.

Figure 5: The dialog at starting the setup. The disclaimer must be confirmed.

Figure 6: Query the destination folder. I recommend keeping the suggested path

Figure 7: Answering this question with ’Yes’ deletes the working directory under ProgramData before
installation, which is equivalent to a basic installation. For users who are not knowledgeable, this is
recommended.

Figure 8: The display after successful setup

The installer will automatically create a desktop shortcut to launch

GrblGru

Figure 9:

GrblGru

shortcut

Projects to Try

I would not like, as in most manuals, to start explaining each button of the program individually.
That would certainly be a lot of boring stuff that no one would read.

So I suggest that I introduce you to some small projects that are self-contained. If you understand the
mindset of a program, you can often help in unknown situations. I hope that I manage to show you how

GrblGru

‘ticks’. Using

GrblGru

with guidance, rather than just reading, can lead to faster learning.’.

In chapter 4 I would also like to introduce more details on certain topics.

4.1

Project 1, Cut out the Moose

In this first simple project, I would like to show how to cut a small figure, in this case a moose (elk,
elch), out of a 3mm thick plywood board. So let’s go!

Figure 10: The moose or elch (the MDF variety)

4.1.1

Load Geometry

First of all, we need the geometrical data of the model. This is obtained from a DXF or SVG file.
Under

C:\ProgramData\GrblGru\ExampleData

you will find a lot of example files, including the file

Elch.dxf. To load this file we go to the Menu and under the item File - Import DXF, find and select
the file Elch.dxf in the displayed window.

And there it is, the first big surprise. The Moose is too big! Do not worry, our geometry can easily be
scaled. For this we activate the button ’2D Scaling’ on the toolbar and set a factor of Fx = 0.3. If the
box is checked to the right, the factor Fy is automatically set to 0.3 as well. Close that Window.

Figure 11: The display immediately after loading - Big Moose surprise

See also chapter ’Loading geometry data’

4.1.2

Jobs and Job Templates

Next,

GrblGru

has to know what it should do with the geometry data. For example, which tool

should be used, what depth to cut, which feeds and speeds should be used, etc. I call these things
a Job in

GrblGru

. As you can imagine, there are some data types that you have to re-enter each

time. To simplify this data input there are Job Templates that can be created once and then used
repeatedly by simply loading them. In this exercise we will create a Template with the fitting name
’Cut 3mm plywood’, which we can use whenever we tackle similar projects.

It is particularly easy to create a Template if you already have similar templates. During installation
some startup templates are already included which we can easily change. For this we change to the
2D-view, Press the 2D Button (top left of screen) and take a closer look at the tree display on the left
side. We see the 5 main nodes:

•

Tools

•

DXF Templates

•

Job Templates

•

Drawings

•

Jobs

With a click of the left mouse button on the small plus sign in front of the respective node name, the
tree is opened. Opening the ’Job Template’ node, we get the following view:

Figure 12: The Tree display in the 2D view

$background image$

Next, let’s use a copy of the ’Cut without tabs’ template to create our template. For this we click with
the Right mouse button on the ’Cut without tabs’ template and select in the Context Menu ’Copy’.
At the bottom of the list a New Template appears “Copy from: Cut without Tabs”. Click with the
left mouse button to look at the content in the properties window.

Figure 13: The display after successfully making a new Template.

Also accessible via the context menu is the function ’Rename’, which we can use to give the template
a descriptive name. In this case, maybe ‘Cut 3mm Plywood’

Figure 14: Rename the Template

Let’s have a look at the properties window in the bottom part of the dialog. Here I would like to focus
on the most important values for the moment. For the sake of simplicity, close the chapters ’General’,
‘Type of Tool’ and ’Special’ by clicking on the small arrow ‘v’ to the left of each heading.

Figure 15: The Properties window

The following numerical values are not real values. They were arbitrarily chosen by me to represent
certain facts. In particular, these feed values are a little imaginative and one finds everywhere a lot of
(also different) opinions, recommendations and also concrete calculations.

•

Depth of Increment

Here we enter the depth that we allow the bit per pass. For example, enter 1.2mm. This Increment
ensures that any differences in the height of the plywood and other small inaccuracies do not
lead to the bit not completely cutting through the material at all points. (So that I do not ’shred’
my spoil board so much, I often put a piece of cardboard under the workpiece).

•

Sum of Increments

Since we want to cut 3mm plywood, we enter as Sum of Increments 3.2mm.

GrblGru

calculates

3.2mm infeed total divided by 1.2mm infeed depth = two passes with 1.2mm infeed and a third
pass with the rest, so 3.2mm - 2.4mm = 0.8mm

•

Plunge Feedrate

is the speed at which the cutting tool lowers into the work material.

•

Cut Feedrate

is the speed at which the tool forms the contour of cut.

•

Rapid Feedrate

is the Speed with which the tool travels outside the material in the ‘safe’ clearance plane.

•

Clearance Plane

is the Safe Height Above the workpiece to be cut. The cutter lifts off to the top and it safely
moves from one contour to the next. Any movement at this level must be collision free!

•

Cut direction

Here you can choose whether to work in the conventional or in climb direction with the cutter.
CCW or CW

•

Bit Radius Compensation

is choice whether the tool path should be corrected to follow the INSIDE, OUTSIDE or ON
THE LINE (none) of the contour cut. This makes it possible to produce the same parts, even
with different cutter diameters.

•

Type of Radius Compensation

the Tool type has an influence on the way the calculated

contour is equidistant from the cut path to compensate for the different tool types. Choice of
ROUND, SQUARE and NORMAL.

•

Tool Identification

The type of Cutting Tool to be used is selected here. I will go into that in the next chapter.

•

Number of Tabs

tabs are small connections between the cut out model and the base material.

These prevent movement of the incompletely cut out part. They must be removed by hand with
a sharp knife or small saw after completing the cutting process. They should therefore be as
small as possible and be in easily accessible locations. For this exercise enter 3 Tabs.

•

Tab Width

eg 5mm

•

Tab Height

eg 2.5mm

•

Tab Style

eg SQUARE, ROUND, or TRIANGLE

4.1.3

The Tool Selection

As we have just seen, in a job you choose a tool name from a given list.

Figure 16: Tool selection list - Tools (Default tools)

The basic idea is to save all the geometric data of the tool under the tool name. The Tool Name
contains the information about which tool type, tool diameter, cutting angle, etc.

GrblGru

created the node ’Tools’ in the tree view and added some tools as examples. In the proper-

ties window, a small sketch and a photo are displayed for each tool. Of course, you can also add your
own tools, Copy, Rename, Save and Load. This is similar to what we’ve done in Job Templates. A
click with the Right mouse button opens a context menu in which various actions can be selected.

Figure 17: Existing tools in tree view

4.1.4

Elements of the 2D view

Figure 18: Elements of the 2D view

Let’s take a quick look at what’s going on in the 2D view. First in the tree view on the left choose
Drawings and expand it. We can see that

GrblGru

detected 2 tool paths from the DXF file. When

clicking on one of the tool paths, the respective path is marked Red in the graphics window. A click
+ ALT key on one of the lines in the graphics window reversely marks the respective path in the tree
view..

The

button in the toolbar shows the dimensions of the drawing (brown rectangle). (If not visible

click the Stock Box button on the top ribbon panel). These are also displayed at the top left (126.0
x 148.4 x 0.0). You determine the minimum amount that your work piece should have. The scaling is
also visible here X=0.3, Y=0.3..

Another important point is the location of the Reference Point (Red+Green Cross). This is the posi-
tion where the cutter begins its trajectory. It can be selected via the “context menu ? that opens with
a click of the right mouse button. It can be moved under RefPkt tab eg Top Right, Center, etc.

Also very important is the

button on the far left of the small ribbon toolbar above the graphics

window. It puts the graphic in screen-filling view. So if you can not see anything, this button is lways
the first choice. This also applies to the 3D window. The other buttons show other views.

4.1.5

Assign a Job to the Geometry

Ok, now that we’ve created a Job Template we need to create a real Job by combining a Geometry
to a Job Template. To do this, we click on the outline of the moose with the left mouse and press the
ALT key. As a sign that it has now been selected, the outline is now highlighted in red.

A click with the right mouse button opens a Context menu in which we can select one of the existing
Job Templates. Select Create Job, then Cut 3mm Plywood template with Left mouse clicks..

During this process, a Job is assigned to the selected Geometry Path.

GrblGru

now has all the

information on how to edit this path.

Figure 19: Create a Job

The result is a New entry in the Tree view under the ’Jobs’ node called Job Toolpath 0. In addition, the
graphic shows the Path of the Tool (green outline) and the Positions of the Tabs (brown rectangles)
and Starting Point (blue triangle).

Figure 20: After creating the job

4.1.6

Starting points and Tabs position

Tabs and Starting points are arbitrarily positioned for irregular geometries. You can easily Move Tabs
to any other position by pressing the left mouse button, hold down, dragging and releasing. It makes
sense to choose places that you can easily reach later to remove the bars with a knife, a saw or a file.
Of course, they should be distributed in such a way that they give the part the necessary support.
Try moving the Tabs around now.

4.1.7

The Second Job

Now that we have successfully created the first Job, we can now tackle the next Job. To do this, we
click on the Eye of the moose with ‘left mouse button + ALT key’ and then create a Job again with
Right Click, Create Job, and use the Job Template ’Cut 3mm Plywood’. In the tree view, this second
Job Toolpath appears under the Job node. Notice the light Blue triangle Start Point. Left Click on
the new Job Toolpath 1.
?
In the Property window we must change the parameter ‘Cutter radius correction’ to INSIDE, so that
the cutter only cuts the Inside of the eye. We don’t need Tabs in this case, so we can change ’number
of Tabs’ to 0.

By clicking with the right mouse button on one of the Job Toolpaths, we are provided with a Context
menu, with which we can set individual Jobs Active or Passive (Inactive). The Cutting Sequence of
individual Jobs can also be changed with the menu items ’Higher’ or ’Lower’.

For example, it is advisable to first carry out all work inside the part to be cut out first and only to
cut out the outside part at the end. This avoids the tabs having to absorb the cutting forces of the
’interior work’. Try selecting Job Toolpath 1 (the Eye), Right Click, select Up to do this Job first.

The Toolpath generated is now displayed as Green with the non cutting tool movements in dark Blue.

Figure 21: Moose with corrected tabs and created jobs

4.1.8

Dimensions of the component

At the top left of the 2D work area is described the dimensions of our component in the raw state. In
our example that is the 3mm plywood board whose required Minimum dimensions were displayed in
the 2D view at the top left (126.0 x 148.4). The 2D work is finished now..

Now return to the 3D view and take a look at the ’Stock’ box with its 3 parameters. Click the 3D
button.

Since it makes sense to make the base material a little bit larger for example, Bounding Box is In-
creased with the parameter

’Bounding’

enlarging corresponding amount on all 4 sides.

The parameter

‘V Offset’

can be used to enter an allowance in Z-direction, eg . the height of a holding

vice, a pad of cardboard, or equivalent.

Finally, the parameter

’Thickness’

, whose name indicates the material thickness. With the Stock

Box button

in the toolbar the stock material can be shown or hidden.

Figure 22: Display of the workpiece in the 3D view

4.1.9

Start Position Marker

Since I do not use limit switches on my machines I can only introduce my way of doing things here.
The procedure using a homing+limit switch reference is correspondingly different..

As a rule, I work in the front left corner of my machine. So I fix my work piece there and position
my XY axes so that the cutter tip is located just above my planned starting point (bottom left of the
work piece). Then I carefully lower the Z-axis until the cutter just touches the component. Often I
simply turn off the supply voltage of the motors briefly and turn the Z-axis by hand a little lower. A
sheet of paper (about 1 / 10mm) serves as a good distance check between cutter and work piece. A
Touch Plate could also be used..

Next I press the ’

Origin

’ button.

This completes the process both in the graphic and the work piece. The reference point of the virtual
loaded geometry (and thus also the workpiece) is relocated to the tool tip and the Z-axis is positioned
so that the lowest point of the cutter touches the top of the workpiece..

This is why I always set the Reference Point of the geometry to ’lower left’. As a result I have the
maximum positive X and Y distance available.

Historical Note:

GRBL comes from the early days of CNC machining. The default Homing point is at the Rear Right
with the Z axis all the way up. This places the entire work volume in Negative Space. This makes a
kind of sense since milling Removes material from the top down - a Subtractive Process.

When 3D Printing came along much later the homing point was set at the Bottom Front Left with the
Z axis all the way down. This places the work volume all in Positive Space. The printer Adds material
from the bottom up - an Additive Process.

It is simpler to just position the origin described at the top of this page. No Homing needed, no limit
switches and no confusion.

4.1.10

The Tool Path

To control the individual tool paths more accurately you can click the button ‘Show Machine’
to turn the machine image off. In order to increase the contrast, the background colour is also changed.

The Green line showing the Tool Path is switched on / off with the NC button.

This represents

the path of the tool. In combination with the SHIFT key the movements on the Safety Plane can also
be made visible. The Tabs positions are shown as small notches in the Green Line.

The display of the White Geometry lines is controlled by the 2D button.

Figure 23: Visible in the marked rectangle is one of the tabs..

4.1.11

Preview

The Preview (Eye button)

on the toolbar can be used to show what the result will look like

before the job is run.

Figure 24: The preview shows what the work piece will look like

Figure 25: A tab enlarged

4.1.12

Save Project

At the end of the CAM work, what has been chosen so far should be saved as a Project. For thisyou
find in the Menu the entry

’Save project as ...

’. Geometry and Jobs are stored in a Project File

under your chosen name and can be reloaded at any time.

It is recommended to save the project as you go. This saves a lot of frustration in the event of a
faulty operation or computer crash. It is also helpful to create an easily found folder Outside of the

GrblGru

folder to save your work in. This way it is not accidentally lost when

GrblGru

is upgraded..

Figure 26: The menu item ’Save project as ...’

An Appropriate Location
Save your project, job templates, tool photos, anywhere outside the Gr-
blGru directories eg. under

C:\MyGrblGruData

. This prevents your files

from being accidentally overwritten during an update.

4.1.13

The Generated Gcode

If you also use

GrblGru

as a G-code Sender, you just press the ’Start’ button and the G-code is

generated by the CAM module. The GCode will be sent to the

GrblGru

Sender as the program

executes in the Virtual model. You can watch the virtual tool move over the Geometry to make sure
the program is executing as you thought it would. The model can be rotated and zoomed while the
virtual work is progressing. The GCode will scroll up in the lower left window..

If you use another GCode sender program like Mach3 for control, you can also easily save the gener-
ated G-code for use later.

1) By pressing the Wrench Button in the tool bar the GCode is opened in a Text Editor. If you need
to change some aspect of the GCode generated this is where is is done. The edited file can be saved
in a location you specify.

2) By Pressing Shift+Wrench Button the ‘Save As. . . ’ page appears preset to save as a NC (Nu-
merical Control) file suitable for use later by

GrblGru

or other GCode Senders. Choose a suitable

location to Save this file so it can easily be found later. Alternatively, you can just choose the file

C:\ProgramData\GrblGru\TempNc.nc

Location to Save the Copy

After your work is saved you may decide to work on another project. Press the Large Red X button
to Clear the Workspace of any jobs.

4.2

Project 2: DXF template, the Coffee Cup Traye

In this project, I would like to show how to use and modify a DXF template to create a simple coffee
cup tray from 6mm MDF material.

Figure 27:

4.2.1

Loading Geometry Data from DXF templates

This time instead of loading the necessary geometry from any DXF or SVG file, we use one of he
DXF Templates.

GrblGru

periodically adds to the List of Templates. The following Templates are

currently available::

•

Rectangle

•

Triangle

•

Ellipse

•

Breadboard

•

Spur gear

•

Box

•

Bolt Circle Calculator

•

Core Hole Making

•

Puzzle Box

To choose a Template

, left-click on the DXF Template Folder in the Tree Display to the Left of

the graphic window. As a simple example Choose the DXF Template ‘Rectangle’, which creates a
rectangle with rounded corners. The graphic window is updated immediately.

The Template Parameters Window appears below the Tree Display Window. As you enter the Height,
Width, and Radius,

GrblGru

will generate the corresponding geometry in the graphic window. This

can then be saved and used, or used as a part of another DXF model. Press the large Red X to clear
the workspace.

Figure 28: The simple DXF Template Rectangle. Specify Height, Width, and Radius of Corners

see also chapter ’DXF templates’

4.2.2

The Box Template

For our Coffee Cup Tray example choose the Template ’Box’. With this Template it very easy to
produce Finger Joint boxes. Once again, the Properties Window at the bottom left appears for input
of the Height, Width, Depth and material Thickness of the box. In addition, you can also determine
the Number and Size of Tails and Pins. These will interlock to form the box corners..

For each choice, changing the values in the property window immediately updates the graphical dis-
play. Try it out for fun..

Figure 29: The DXF Template ’Box’

For anyone who wants to build a box instead of our coffee cup tray at this point the work is almost
done. All you have to do is create a Job for all or some of the parts. This can be done via the Right
Mouse Click Context Menu

as before with the Moose/Elk example. This Job will allow generation

of the Toolpath GCode which can be Saved or Run.

Figure 30: Create a job for all parts

See also ’Various options for creating jobs’

The positions of the parts are chosen by

GrblGru

so that you can immediately see how they all come

together. This is not optimized for space-saving in the milling process..

To optimize placement, you can Export the Parts as a DXF. Load them back into

GrblGru

or into

the 2D Editor of your choice and position or change them as you like. They can then be saved as an
edited DXF file and reloaded into

GrblGru

for further processing.

It is possible to select the parts individually (Left mouse click), or in suitable groups (Left mouse click
+ Ctrl) for processing with Jobs. To do this a context menu can be opened again by Right Clicking
on a marked contour.

You can also Show or Hide any of the parts by selecting with Left click and then with the Right click
Contest menu choosing Hide or Show. If you lose a part, choose Show All and it will reappear.

Figure 31: Context menu - choice to hide parts

4.2.3

Save Geometry Data

As already mentioned ,

GrblGru

already has the geometry data internally available after activating

a Template. This is why is it possible to Export them so easily as a DXF or SVG..

Figure 32: Menu choices for Exporting/Saving the geometry

4.2.4

Modification of the Geometrye

Saving the geometry data allows us to load that data into a 2D editor and modify it accordingly. In
the following Figure you can see how you can do easily something else with the Box.

The redesigned Box result can be Exported as a DXF file and then Loaded back into

GrblGru

create Toolpaths.

Figure 33: Redesign the Box in the 2D editor

If you want to make sure that the parts fit together correctly, you can test this model in a 3D CAD
program like OpenSCAD. If this program is loaded on your computer in its default location, there is
an option for it in Settings and it will appear as a convenient tab next to the 3D tab. It can then be
launched from

GrblGru

Figure 34: Check in a 3D program, . . . it fits! :)

4.2.5

Create Job with ‘Corner Overcut’ Parameter

Now having made and saved the Box geometry data we are still missing an important process. All
we have to do is create the Job again. Since this is a simple procedure we Select the DXF Template
‘Box’, specify the size parameters and Change the Parameter ’Corners Overcut’ in the Special section
at the bottom of the Parameters window.

This parameter ensures that inside corners are slightly Over Cut so that the teeth fit together. This
is necessary because you are trying to cut square corners with a round bit. This is also called Dog
Boning because of the shape of the cuts when done.

Figure 35: The parameter ’Corner Overcut’ in the Cut Job

Figure 36: The effect in the tool path display

One can clearly see the effect of the OverCut corners in Preview (press the Eye button). You can see
that during milling the tool will cut a little deeper into the corner. As a result, the fingers of the joint
will fit completely together. There will be a slight gap at each corner when the box is completed..

For people who do not want to use this feature, there is an alternative .... file each joint by hand :)

Figure 37: Check in the 3D program, ... it fits :)

4.3

Project 3: Bitmaps Drilling, the Smiley Face brooch

The possibilities of a CNC of drilling simple hole templates is easily overlooked. The practical benefits
of the small project presented here can certainly be called into question, but it describes all the
necessary settings that you need for drilling other patterns (even larger) like a Spoil board. This also
demonstrates importing and using a Bitmap.. :)

Figure 38: A simple ‘Smiley Face pattern’

4.3.1

Drilling

The basis of a hole is a circle. The diameter of the circle does not matter. The Drilling will always
take place in the Centre of the selected circle..

To create a Drill Template with multiple holes, you will need a DXF or SVG drawing of what you
want to drill that contains Circles and select them for drilling..

Figure 39: Drawing Expansion in the Tree of the Drawings that can be used to drill.

4.3.2

Loading Bitmaps

However, there is a special feature that we want to use for this project. When importing Bitmaps,
either via the menu functions or with the aid of Drag & Drop, white pixels are interpreted as 1mm
circles. While choosing Import, Press the SHIFT key to load all the non-white pixels as circles. The
example Smiley.bmp is located in the folder

C:\ProgramData\GrblGru\ExampleData\BMP

Figure 40: The BMP imported

without

Shift

Figure 41: The BMP imported

with

Shift

If you want to Enlarge or Reduce the distances between the holes or work with a drilling tool other

than a 1mm drill, you can do it all with the Scale function

For editing icons or BMPs, I recommend the free program IcoFX.

4.3.3

The Operating Mode ’DRILL’

To create a Job you can use the ready-made Job Template ’Drilling’, the essential feature of which is
the ’DRILL’ mode.

Figure 42: Operating mode ’DRILL’

The most important parameters besides the speeds are the Infeed depth (depth of the single hole) and
the Infeed sum (end depth of the hole). The remaining parameters are self-explanatory .The procedure
is to drill to a certain depth and then pull the drill out of the hole to remove the chips. Thereafter,
the process is repeated until the final depth is reached. This is also called Pecking (like a bird).

Figure 43: Parameters of the operating mode drilling

Finally, here is the 3D view of the process. The display of the tool paths can be combined with pressing
the NC button. In combination with the Shift key, the paths of the tool are also displayed on the safety
level.

Figure 44: Drilling in 3D view

4.4

Project 4: Projection onto a rotary axis, the Viking bowl

4.4.1

Prerequisites

The prerequisite for successful milling of a projected DXF or SVG sketch is the exact indication of
the relative position of the probe origin to the tool origin. !

During the measurement, the probe and tool move simultaneously. To
ensure that the tool does not collide anywhere, it is best to remove it
during measurement.

Figure 45: Offset of the probe

4.4.2

Scanning the workpiece

1. Position the probe over the starting point. The height above the component is not important.

But the probe must be positioned exactly above the rotation axis. Accept this position with the
’Origin’ key and start the measurement.

Figure 46: Scanning

2. After the menu item ”Create STL” has been executed, a new STL object is created from the

existing measurement points, which can then be used for the projection.

Figure 47: The new STL object from the measuring points

4.4.3

Load, scale and position sketch

1. Remove the probe if necessary so that it does not interfere during milling. End the measurement

dialog and position the tool at the same point where the probe was previously located. The
height is not important.

Figure 48: Tool at starting point

2. Now load a DXF or SVG sketch and position and scale it

ONLY

with the 2D data manipulation

dialog. The axes X,Y, and Z must

NOT

be changed.

Figure 49: Scaling and positioning the sketch

For better positioning you can also hide the machine parts with the toolbar button ’M’ and look
at the workpiece from above (small toolbar button).

Figure 50: Top view

Figure 51: The buttons to look vertically from above

4.4.4

Create a job and start

3. Now go to the 2D view, select the paths to be milled and create a projection job.

Figure 52: Job creation via right mouse click context menu

Figure 53: Example of a projection job

4. Back in the 3D view you can see how the green tool path was projected onto the workpiece.

Figure 54: The tool path

Figure 55: The tool path

All that remains is to switch on the spindle and press the Start button. :)

Details on other Program Operations topics

The following chapters are a disorderly collection of descriptions of specific topics.

5.1

3D graphics

To get directly to the point, for those who have never dealt with 3D graphics before, it is a little
difficult in the beginning. But after a short period of practice, you will be much more comfortable.
It’s fun to master these graphics and you just see a lot more than 2-dimensions : )
Commands to control the 3D View

•

Show Entire Model,

, Front,

, Top,

and Side View

These are on the small Toolbar Ribbon above the Graphics Window. The wireframe icons are
there as well for the 2D view.

•

Zoom window

In the Graphics Window Press and Hold the Left mouse button and draw a Window from top
/ left to bottom / right. Release the button. The Graphics window will zoom into that area

•

Pan = Move Graphic

Hold down the middle mouse button and move the mouse..

•

Zoom = Increase / Decrease

Use the Mouse wheel

•

Orbit = Rotate the model in 3D

Hold the right mouse button and move the mouse

•

Selecting the Midpoint of the Graphic

A double-click with the left mouse button on a Node of the Graphic fixes this as the pivot point
of the orbit function in the centre of the screen.

The View Commands above can be shown / hidden in the Graphics Window using the Large Yellow

button

in the toolbar.

Figure 56: Quick help for the graphics functions

5.2

Options to Load Geometry data

The

GrblGru

CAM processor first needs 2D geometry data as the basis for its calculations. These

can be read in both

DXF

and

SVG

formats. The Loading can be done in several different ways:

5.2.1

Via the Menu - Import DXF or Import SVG

Figure 57: Loading the geometry data via the menu

5.2.2

With Drag & Drop

A very convenient way of reading is to simply load the files using drag & drop. Click on the file to be
loaded in Explorer with the left mouse, drag it to the GrblGru graphics window and then release the
mouse button..

5.2.3

By selecting Recent Files

there is the possibility that a current file is on this list to use.

Figure 58: Loading the geometry data from the list of recently opened files

5.2.4

Load With ’Quick Load Last File’ button

Last but not least there is the possibility for the last loaded data to reactivate it with the help of
Hotkey buttons.

Figure 59: Loading the geometry data via ’Quick Load Last File’ button

Unfortunately, there are a lot of different DXF and SVG formats. So it can happen occasionally that

GrblGru

does not completely load a file. For many DXF editors, you can specify different options or

versions when saving. So if there are any problems, try a different setting first. If that does not lead
to success, please send me your DXF or SVG file so I can see what it is.

GrblGru

has only limited 2D editing functions. I think that most of users already have ’heir own

favourite 2D editor that they are prepared to use and can use more effectively. For those who have
not yet found an editor, I recommend the free program

Inkscape

5.3

Ways to Create Jobs

There are a number of ways to Create Jobs. Depending on what you are doing, one or the other
method may be more suitable.

5.3.1

In the Tree View: Drawing

Figure 60: Shared job for the entire geometry data

Here all geometry data from all layers are provided with a Job. It is often the case if you have a
Drawing with many small parts that just need to be cut out. Selecting the top one makes this easier.

5.3.2

In the Tree View: Toolpath

Figure 61: Job for geometry data of a layer

Here all geometry data from all layers are provided with a job. When clicking on the tool path, the
corresponding area is highlighted in red in the graphics window.

5.3.3

In the Tree View: Layer Name

Figure 62: Job for geometry data of a Layers

An extremely effective method for lazy people (like me). Jobs are automatically assigned based on the
Layer names used..

For example, suppose you have similar tasks to repeat a number of times; parts that need to be cut
out, areas where pockets have to be cut or places to drill. For this you have created the templates
’Cut’, ’Pocket’ and ’Hole’, which you now have to assign to the individual areas of the graphic. If you
have to do these frequently, it makes sense to do this during design in the 2D editor. With all 2D
editors there is the possibility to draw on different Layers and also to name them..

If you give the Names of your Templates to your Layers, GrblGru will automatically create corre-
sponding Jobs from them.

5.3.4

In the Graphics Window: Pull up the window

Figure 63: Mark an area with a window

With the Left mouse button you can create a window by Click-Hold and drawing from Upper left to
Lower Right. The paths in it are highlighted in Red. A subsequent click with the Right mouse button
opens the Context Menu for creating a Job.

5.3.5

In the Graphics Window: Click on Paths

Figure 64: Direct Select Multiple Paths

With the left mouse button, paths can be selected directly. If several paths are to be selected, press
and Hold the CTRL key while clicking the Left mouse button. Selected Paths are highlighted in Red.
A subsequent click with the right mouse button opens the Context Menu for creating a Job.

5.3.6

Last Used Job

Figure 65: Quick selection of the last used job

In the dialog box of the Context Menu, the Last Job selection is made available on the last line
as a Quick selection. This saves the selection in the second dialog if you can select the same job in
succession.

5.4

Options to Mark Elements in the 2D view

In order to assign a process to the objects of a loaded DXF file (ie create a Job), you must be able
to select individual objects. Basically, this can be done either in the tree view or in the 2D graph-
ics. There is an interaction between these two. For example, if you mark a path in the graphic, the
corresponding branch is also marked in the tree view. Likewise item marked in the tree view is also
immediately highlighted in the graphic.

Before I get to the various possibilities of Marking, I would like to clarify the two terms.

•

Element

As an element, I refer to a line, arc, circle, arc, and so on.

•

Path

As a path I define a polyline as consisting of Contiguous or Joined Elements. This means that
there is no gap between any 2 elements. When the end of a path is connected to the beginning,
I’m talking about a closed path.

Selection in the graphics window is done by clicking with the left mouse button in conjunction with
the 3 special keys SHIFT, CTRL and ALT.

•

No special key is pressed

Left Clicking on an Element marks the complete path in which the Element is located. The
Marking of all other paths and elements will be excluded.

•

CTRL key + Left Click

A click on an item to move the marker of the complete path where the item is located. This
means that the marking of a previously marked path will be deleted and an unmarked one will
be marked.
All previously marked paths keep their condition!

•

Alt key + Left Click

Here not the complete paths, but only the individual clicked elements are marked. The marking
of all other paths and elements will be excluded.

•

ALT and CTRL key Left Click

Clicking on a marked item will change the state of the selected element. This means that the
marking of a previously marked element is deleted and a non-marked element is now marked.
All other previously marked elements keep their condition!

This may sound difficult at first glance, but it is not. For elements, use the ALT key, but not for paths.
If you want to collect elements or paths you use CTRL. (as with marking in Explorer)

5.5

DXF templates

DXF templates are configurable generators of DXF drawings . They are very simple use e.g . The Rect-
angle Generator, which generates a drawing of a rounded rectangle after entering the Width , Height,
and Radius parameters . But there are also, for example a Gear template, the Box and Clamping Board.

In each Template changing the values in the Property Sheet immediately makes a corresponding
change of the graphical display. Experiment with this feature.

The following are the currently existing DXF templates are listed below :

•

Rectangle

•

Triangle

•

Ellipse

•

Breadboard

•

Spur gear

•

Box

•

Bolt Circle Calculator

•

Core Hole Making

•

Puzzle Box

•

Clamping Board

5.5.1

Rectangle

Figure 66: Template Rectangle

Simple template to make a Rectangle element or Box.

5.5.2

Triangle

Figure 67: Template Triangle - Simple Triangle

Simple template to cut out a port or to mill a pocket

5.5.3

Ellipse

Figure 68: Template Ellipse

To create a door sign for example

5.5.4

Breadboard

Figure 69: Hole pattern

Can used be to drill one or several nested holes. By entering values in the X and Y direction you make
a grid of holes. This could be used to produce a spoil board for your CNC. It can also specify the
diameters of up to three nested holes. This can make a bored hole, and at the same time the necessary
recesses for a screw head. For each circle a depth and size can be input.

5.5.5

Spur gear

Figure 70: Template Spur Gear

Figure 71: Planetary gear

Relatively complex template for the production of Spur Gears. You can interpret it with complete
spur gears . Take time to make a demo planetary gear shown. For this purpose there is an video below

https://youtu.be/l9u2lKB3kMs

that shows you how with the help of beer cans. :)

5.5.6

Box

Figure 72: Template Box

THE Classic Template . Very helpful to design and make finger joint Boxes.

5.5.7

Bolt Circle Calculator

Figure 73: Template for Bolt Hole Circle calculato

Very practical eg. in the manufacture of different holes in the Model.

5.5.8

Multi Drill Circle

Figure 74: Template Core hole production

Can used for the positioning of small bore holes to help make a much larger core hole.

5.5.9

Puzzle Box

Figure 75: Template Puzzle Box

Figure 76: Test box made of 8mm MDF

My recommendation for a creative packaging of gifts . The generator is calculates a new puzzle pattern
each time..

My tip: Make yourself a record of the solution and never mix parts of 2 boxes. They will never be
assembled again? :)

There is also a short video of Puzzle Box: :)

https://youtu.be/214Bczo-8uw

5.6

USEFUL Free programs to use with your CNC

I have here a small list of programs that I quiet conscience further recommend can :

•

GRBL

3-axis operating system for Arduino UNO. The CNC operating system for public use.

•

g2core

5-axis operating system for Arduino DUE

•

Gimp

A great program for editing of graphics of all kinds. It is worth getting to know all it?s functions

•

Inkscape

An editor for editing SVG files

•

OpenScad

A very useful 3D CAD program. Can be used with

GrblGru

•

7-Zip

A program for packing and unpacking files

•

F-Engrave

THE really good program for Engraving . There is nothing better !

•

Notepad++

A great GCode editor - Can display G code in color

•

IcoFX

A program for editing bitmaps and icons

5.7

Notepad++, a Editor for G-Codee

Press the

button on the toolbar and the generated G-code with the Windows Notepad Editor

window opens. You can also specify your favourite Editor in settings, so

GrblGru

can use that to

display the GCodes created. Notepad++ for example.

Figure 77: Entry in Settings under Extras on the Toolbar

Personally, I always use Notepad ++ because it gives you the ability to colour code certain key words.

Figure 78: Display of a GCode file in Notepad ++

For the GGode generated by

GrblGru

I wrote a special custom language file. This file named

Gr-

blGru

GCode.xml. It can be imported into Notepad ++ under the menu item Language-Import.

When

GrblGru

is installed, the file is stored in the installation directory.

C:\ProgramFiles(x86)\toe\GrblGru

Figure 79: Importing the custom language file

$background image$

GrblGru

uses some files with a so-called Ini structure. This means that these files store their contents

in chapters with keywords. To display these files, there is the prepared language ’Ini file?. So that
Notepad ++ can open a file with the extension ’dat’ immediately with the corresponding language,
there is the possibility to fix a file extension eg ’.dat’ with one language. The necessary dialogue can
be found in the Extras Menu under ’Settings-Style’

Figure 80: Access to dialogue

Figure 81: Assignment of a file extension to a language

Macros

There are situations in which you want to call up certain processes at the push of a button. For exam-
ple, a hole can be drilled very carefully and with several chip removal operations because the material
requires this. In this case, the best result is achieved if the GCode is created by hand, tailor-made for
the required process.

So that this function is always available at the push of a button,

GrblGru

offers an easy way to

create macros. To do this, the macro bar must first be switched on on the settings page.

Figure 82: Switch on the Macrobar

Figure 83: Macrobar at the right side

By pressing the lower button with the name ’EditMacro’ the file Macro.dat is opened in the editor
and can now be edited..

Figure 84: The open Editor

A macro always starts with the macro name in square brackets.
So e.g.

[Macro example 1]

. The name should be meaningful because it will be displayed on the

button in the macro bar.

Figure 85: The buttons of the Macrobar

After that any number of lines with valid GCode syntax can follow.
After the input the editor is closed. After that

GrblGru

immediately updates the macro bar and the

currently entered function can be called by pressing the corresponding button.
The macros are also available after a restart. You can create as many macros as fit on the screen.

6.1

Operating system Macros

Direct communication with the respective processor is to be mentioned as quite interesting application
possibility of the macros. All operating systems Grbl, TinyG, Mega-5X and g2core offer the possibility
to change movement commands and settings via commands.

GrblGru

provides the possibility of

direct communication in the two controller windows.

So you can easily change several settings with the help of macros. The macro listed below sets e.g. all
settings of

Grbl

[SetMyMillingSetings]

$0=10
$1=25
$2=0
$3=0
$4=0
$5=0
$6=0
$10=0
$11=0.010
$12=0.002
$13=0
$20=0
$21=0
$22=0
$23=0
$24=25.000
$25=500.000
$26=250
$27=1.000
$30=1000
$31=0
$32=0
$100=100.000
$101=100.000
$102=50.000
$110=500.000
$111=500.000
$112=500.000
$120=10.000
$121=10.000
$122=10.000
$130=200.000
$131=200.000
$132=200.000

The following macros may also be helpful

[Version]

[State]

[Settings]

6.2

Advanced Macro functionality

The advanced

GrblGru

Macro language is very powerful. It allows the use of parameters, loops and

conditional jumps. There is also the possibility to display parameter values in a dialog box. It is also
possible to enter values in a dialog box.

Parameters must begin with a ’#’ e.g. #Length.

•

Parameter Assignments

#Length = 12.5
#Length = #Diameter

•

Mathematical operations

#Jeff * 2
#height / 2
#Diameter + 2
#Infeed - 2

•

Conditional jumps

if (#FeedRate

50)

{

instructions ...

}

•

Loops

while (#Counter

{

instructions ...

}

Behavior control instructions

•

%Reload

The macros write the generated GCode to TempNc.nc exactly like a job does. If you want to
use a macro, e.g. to switch only the laser on / off, the code previously in TempNc.nc will be
overwritten. %reload saves the old code and writes it back after processing the macro.

•

%NoAutoRun

Normally macros are executed immediately with the keystroke.

’NoAutoRun’

causes that the

GCode

not

is started directly. It must be started explicitly with the green ’Start’ button.

Various dialog boxes are available for displaying and entering data:

•

%message

Example 1: %Message, This is a message without value

Figure 86:

Example 2: %Message, Length = , #Length

Figure 87:

•

%Input

%input,

cylindrical turning

Length of piece

, #Length,

Sum of Increments

, #SumOfIn-

crements,

Dept incremen

t, #DepthIncrement,

Cut feed rate

, #CutFeed,

Plunge feed rate

#PlungeFeed,

Rapid feed rate

, #RapidFeed

The command %Input exists for data input, which displays an input dialog in which values can
be entered. These values are then assigned to the corresponding parameters and can be used in
the macro.

Figure 88: The input dialog

•

%variables

This command is used to display the system parameters and their contents.

Example:

Figure 89: The system parameters

Administration of languages

GrblGru

can manage many languages. Each language is saved in a separate file. The structure is

very simple. Each row has 2 columns. The columns are separated by a ’;’ symbol. The 1st column
contains the key used in the program. It always starts with a ’#’ or a ’ ?’. The 2nd column contains
the text in the respective national language.

Figure 90: Part of Language German.txt

The order of lines within a language file is arbitrary. If you want to create a new language, it is best
to copy the English language file English.txt and replace the English texts with the new texts. Then
the file can be renamed accordingly when saved. GrblGru recognizes all existing language files at the
start and offers them in the language selection dialog.

After a language has been edited, it makes sense to sort all the texts again alphabetically. This makes
it much easier to find searched texts. This sorting can be done via the menu item Sort Text:

Figure 91: The Languages dialog

All language files are located in the folder

Program\DataGrblGru

•

Language english.txt

•

Language espanol.txt

•

Language french.txt

•

Language german.txt

•

Language magyar.txt

•

Language PortuguesBrasileiro.txt

•

Language Russian.txt

How to Import your own 3D Machine Model

A special feature of

GrblGru

is the ability to import your own 3D models. These models are then

used to graphically simulate the loaded G-code.

This chapter presents the necessary steps to import an existing 3D model.

8.1

Can

GrblGru

simulate my machine ?

If you can not find a corresponding model in the list of available machines, you can import your own
3D model. The condition for this, however, is that the type of the model already exists. The type
determines the relations of the axes to each other. For example, whether the tool moves to the com-
ponent, or the tool is fixed and moves the component to the tool. Is the Z-axis traversed when X is
processed? Does an A-axis rotation affect the B-axis or not?

As an example for two completely different types, the following machines are listed.

Figure 92: Example of ’ShapeOko’ type

Figure 93: Example of ’Milly’ type

$background image$

I recommend looking at some of the existing models to make the differences clear. You can find a list
of all machines under the menu item Extras / Machine Manager and can see the corresponding type
under the entry Machine type.

Figure 94: Enter machine type in the dialog of the machine administration

If you need a model whose type is not yet available, please let me know. I will then try to supplement
the corresponding type.

The following types of machines have been realized so far:

•

SHAPEOKO

•

MILLY

•

SPRITE

•

NONY

•

EGGBOT

•

PRINTER3D

•

SHAPEOKO-AX

•

LASER

•

FIVE-AXES-1

•

FIVE-AXES-2

•

FIVE-AXES-3

•

DETTORRE

•

LowRider

•

MpCNC

•

BUX

8.2

Construct the machine in CAD

First, of course, you have to construct the machine in CAD. I do not want to go into that on this
point, because it essentially depends on the CAD system used. To create my previous models, I have
always used the program CREO.
However for construction with CREO there is a little video below:
https://youtu.be/v5m8HKOdHG0

The only important thing in the design is that you align the machine coordinate system as follows.

The X-axis points to the right, Y to the rear, Z to the top. The preferred
Origin of all three axes lies at the Bottom Right Rear.

Figure 95: The machine coordinate system

8.3

Save Modules as STL

At the moment

GrblGru

can only read 3D data in STL format. For this purpose, the axis modules

must be available in this format for the actual import.

Once the complete model has been constructed, the assemblies are assigned to the desired axes and
stored in the STL files. The following file names are expected:

•

Base+.STL

Fixed Basis

•

X+.STL

X-axis;; linear axis

•

Y+.STL

Y-axis;; linear axis

•

Z+.STL

Z-axis;; linear axis

•

A+.STL

A-axis;; axis of rotation

•

B+.STL

B-axis;; axis of rotation

The ’+’ in the name causes the edges of the respective module to be traced and can also be omitted.
All files are first stored in any directory.

8.4

Create a new machine in the Machine Manager

The next step is to start a new machine first. To do this, you can find the following dialog in the Menu
under the item

Extras / Machine Manager

The easier entry of the machine data is facilitated by first selecting a machine of the type that you
would like to create in the first line. As a result, many data are already preallocated.

Simply enter the name of your model in the first line and press the button

”Add new machine”

Figure 96: Dialog of the machine administration

8.5

Import STL files

After creating all STL files and creating the new machine, you can now load the files in the Machine
Manager. To do this, select the directory with the STLs via the ’Browse’ button and confirm the
queries.

Please DO NOT enter the path manually. That does not work !

Figure 97: Import of STL files in the machine management

8.6

Reading out control values

The machine can now be selected and displayed in the program.

Figure 98: List of available machines

8.7

Tool Position

It is likely that the tool may not yet be displayed in the correct position. To do this,

GrblGru

needs

the coordinates of the tool origin in the machine coordinate system.

These coordinates can be taken from the CAD directly at the design, or measured retroactively with

GrblGru

. To do this, click with the left mouse button and the pressed SHIFT key in succession on

3 points of the circle or polygon. The coordinates of the centre point are then displayed in the status
bar and must be entered in the machine administration dialog. The measurement is reset by clicking
+ SHIFT key off to the side

Figure 99: Measurement of tool origins

The X, Y and Z components of the coordinate are then entered in the dialog of the Machine Manage-
ment under Number 6. Tool.

Watch out ! Remember to press the button ’Accept data’ after the entry
or any changes are lost.

Figure 100: Entering the Origin tools

8.8

Rotary Axes position and direction

The designations of the two axes of rotation A and B do not correspond
to the basic rules for axis designations for purely pragmatic reasons.
This is the reason why, in the following example, the rotation axis that
rotates around the Z-axis does not bear the name C, but can be called
A or B.

In order for

GrblGru

to handle the axes of rotation correctly, a point on the axis of rotation and

the direction of the axis are required. To measure a point on the axis of rotation, proceed analogously
to the tool origin. The direction can usually be determined without measurement, because it usually
extends in the X, Y or Z direction. In the example ’lathe chuck’ it points upwards, ie in the Z direction.
That’s why we enter 0, 0, 1 in this case. The input of the direction always refers to the basic position
of the model. So as it was constructed and drawn.

Figure 101: Measurement of a point on the A-axis in CAD (but can also be measured with GrblGru)

Position and direction of the A-axis are entered in the dialog of the Machine Manager in Chapter 8.

Figure 102: Entering the position and direction of the A-axis

For the sake of completeness, here is the same game with the B axis. The direction here is the X
direction, that is 1,0,0

Figure 103: Measurement of a point on the B axis

Figure 104: Entering the position and direction of the B axis

100

8.9

Input of the Reference Position

In Chapter 3 you can specify the position of a reference point on which the model is positioned when

you press the Toolbar button

. In conjunction with rotary axes, it has proved helpful to place the

reference point in the middle of the A-axis.

The position of the X and Y components can be calculated simply by subtracting the A-axis position
and the tool position. Z stays at 0.

−

(1)

−

(2)

= 0

(3)

(4)

−

570

−

(

−

45) =

−

525

(5)

−

425

−

(

−

175) =

−

250

(6)

= 0

(7)

Figure 105: Entering the position of the reference point

101

Figure 106: Reference point = center A-axis

102

8.10

Limits (limit switches)

If you want, you can enter the axis limits in Chapter 4. When the V in the settings is on monitoring,
the axes remain in manual mode upon having reached the end position.

Figure 107: Dialog Settings

103

8.11

Remaining settings

Please make sure that you have not accidentally set one of the option buttons. These are only intended
for special machines and can considerably influence the machine function.

104

Figure 108: Normal position of option switches = NO

105

8.12

Special models (lathes)

In principle, the creation of Metal Lathe 3D models works just like the milling. However, there are
some supplements that I would like to talk about here.

Figure 109: The lathe components

First of all, the 3D model

MUST

be drawn in the following coordinate system:

•

The origin lies in the centre of the chuck. If you do not take that into account, the rotation of
the food will not work.

•

The chuck is saved as

y+.stl

•

The blade holder m should be positioned so that the leading edge is at Y = 0. It is saved under

m+.stl

•

The chuck must be drawn so that a clamping claw is perpendicular to the top.

•

The vertical jaw must be saved as

s1+.stl

. Then the other two jaws follow with counterclockwise

view of the chuck.

•

The handrails are saved as

h+.stl

hx+.stl

and

hy+.stl

•

The tailstock is saved as

r+.stl

and the quill as

p+.stl

•

Tool changers are saved as

m+.stl

like a normal knife holder.

106